the blog of LAKE, the Lowndes Area Knowledge Exchange

Citizen dialog for transparent process

Friday, 28 December 2012

2012 solar deployments driven by Moore's Law price reductions

Moore's Law for solar is about decreasing price per Watt,
or more Watts per dollar.
Here's an example of a common confusion, to think it's about efficiency:

“The curve will obviously become asymptotic at some point, ie,. the rate
of improvement will flatten out, so we end up with a sort of squashed
"S" shape curve, because you can't get more than 100% efficiency —
36 watts/m2 or so.”

And indeed efficiency probably will flatten out soon.
But it's not solar
efficiency that's improving by Moore's Law: it's price per watt.
That can keep improving for a long time.

"Just to give you perspective," Resh said, "in Washington, D.C.,
where I live, when I installed solar on my house six years ago, the
average install cost was about $14 a watt. Today it's about $4 a
watt."

Here's another comparison, this one just for solar panels.
In 2005 the first set of solar panels we got cost $670 each
and produced 170 Watts DC each, or $4.94/Watt.
In 2011 our second set of solar panels cost $562 each
for 235 Watts DC each, or $2.39/Watt.
That's more than 50% price decrease for solar panels in six years.
(I can't compare inverters or support structures directly,
because those were sized so differently, but those have also
come down in price, helping lower the overall install cost).

Year

price /Watt

price /panel

Watts /panel

Dimens.

square inches

Watts /100 sq in.

Model

2005

$4.94

$670

170W

50x39"

1950

8.7

KC 170

2011

$2.39

$562

235W

39.1x64.6"

2525

9.3

Sharp ND 235 QCJ

2012

$1.32

$310

235W

39.1x64.6"

2525

9.3

Sharp ND 235 QCJ

Meanwhile, the Watts per surface area hardly changed, from about

8.7 Watts per 100 square inches to about 9.3,
which is only about 7% different, so little it could be due
to framing rather than the usable solar PV area.
The 2011 panels produce more Watts simply because they're
bigger.
Both models of panels (2005 and 2011) are around 15% efficiency,
according to their specs.
So it's not efficiency that's improved in commercial solar
panels from 2005 to 2011: it's price per watt.

And those same 2011 Sharp ND 235 QCJ panels now cost $310 each at
the end of 2012,
for $1.32/Watt, or another 45% price decrease in one year.
The 2005 and 2011 prices may have had some installation costs included,
but whichever way you look at it, solar PV price per Watt has come way down.

In fact, while analysts were paying attention to fracking this year,
a record number of solar panels were being slapped on roofs —
enough to produce 3.2 gigawatts of electricity.

And there's a lot of room for expansion:

That sounds like a lot, but solar is still providing just .05
percent of the country's total energy.

Which is a big reason we'll see Moore's Law for solar continue
for a long time yet:
we've hardly even reached mass market at this point,
and as we do, economy of scale will keep pushing prices down.

The bulk of solar growth is happening at businesses; companies are
installing panels on roofs so that they don't have to buy as much
energy from the grid. State and federal policies are making that an
easy decision for companies. Businesses who install panels can
qualify for grants and tax breaks, and laws in 38 states require a
certain amount of electricity to be generated by solar, wind and
other renewable sources.

Businesses can often get financing for solar;
private individuals (and small businesses) often can't,
at least not in Georgia, with that
1973 Territorial Electric Service Act
in the way.
Imagine the solar boom in Georgia, with jobs and reduced
electric bills for south Georgia,
if the legislature changes that law!